On the surface, Sackler’s 25th anniversary gala was simply a grand party. To insiders, it was belated public lovefest for the Asian art gallery — and the end of a private dust-up between a major donor and the gallery’s Smithsonian overseers.

Eighteen months in the planning by co-chairs Susan Pillsbury and Ann Nitze, Thursday’s black-tie bash for 400 guests boasted VIPs draped in diamonds, rubies and jade, visitors in colorful Far East formal wear, and a few decorative royals: Iran’s former Empress Farah Pahlavi, Princess Michael of Kent, a handsome maharaja or two.

But the star of the night was Dame Jillian Sackler, British-born widow of museum founder Arthur Sackler and fierce champion of his legacy. She donated $5 million to the gallery earlier this year and presided over the gala, thus effectively ending her behind-the-scenes dispute with museum director Julian Raby and the Smithsonian.

Violinist Hahn-Bin performs at the gala. (Tony Powell)

Thirty years ago, the Smithsonian convinced her husband to donate 1,000 pieces of Asian art and artifacts — valued at $75 million at the time — to establish a world-class museum in Washington. “We were very proud to give to the nation,” she told us. “It was obviously a marvelous thing to be the basis for the national collection.” The gallery officially opened in 1987, just four months after Arthur Sackler died.

But the Smithsonian already had a museum devoted to traditional Asian and Asian-inspired American art: the Freer Gallery. And that collection was donated in 1923, with strict provisions that curators could add to it but never lend out pieces nor exhibit art borrowed from outside. The Sackler gift came with no such strings, which better positioned it to mount the kind of blockbuster exhibitions now in vogue. The two collections were combined into one museum but, over time, Jillian Sackler believed the Sackler got short shrift when compared with the Freer in name and promotion, contrary to the terms of the original bequest.

Things got dicey enough that D.C. power lawyer Bob Bennett was quietly recruited a couple years ago to broker a peace between Sackler, Raby and Smithsonian Secretary Wayne Clough, who, we’re told, wanted to signal assurance to future donors about honoring terms of their gifts. It worked: The Sackler now has a higher profile, and Bennett was publicly hailed by Sackler Thursday night for his pro-bono work on her behalf.

Raby (who now officially carries the title “The Dame Jillian Sackler Director of the Arthur M. Sackler Gallery and the Freer Gallery of Art”) had nothing but glowing tributes for both Sacklers and their contributions. Sackler was equally effusive about Raby’s leadership and the harmonious relationship between the Sackler and the Freer.

Raby told us he sees no conflict between the two institutions; instead, he considers them complementary halves of an artistic whole. “You have two very different buildings with very different characters. One is almost like a temple of calm; the Sackler needs to be much more lively, innovative, risky. What I want is a contrast, as opposed to some undifferentiated style.” The gala raised $1 million, which is dedicated to the Sackler’s contemporary collection.

The night ended with a performance by violinist Hahn-Bin, the Korean-born classical music’s provocateur who startled the crowd with his virtuosity and jarring appearance. Guests walked out with three — three!— goodie bags with Sackler-related swag.